The Florentine Diamond

Following on from our recent post about the Three Brethren Jewel, another interesting diamond that is lost to history is the Florentine Diamond, a 137 carat yellow stone. It was first definitely documented in the collection of the Duke of Tuscany, the future Ferdinand II (a member of the Medici family), 1610-1670, though it was rumoured to have once been owned by Charles the Bold, Duke of Burgundy, who coincidently also once owned the Three Brethren.

Records indicate a weight of 139 old carats, and a colour approaching Citron. It had an irregular octagonal outline, rose cut on both sides, with 144 facets. This can indicate an Indian origin, though this is mere speculation. It is believed to have been first acquired in the late sixteenth century by the Governor of Goa, who sold it to Ferdinand of Tuscany for 35,000 Portuguese Scudi.

Florentine Diamond copy

The diamond stayed in the collection of the Medici family until the male line ended, and it was willed to the Duke of Lorraine. By 1743 it had become part of the Austrian Crown jewels, following the marriage of Marie Therese of Austria to the Duke of Lorraine, creating the Hapsburg-Lorraine dynasty. (Interestingly, one of the children of this marriage was Marie Antoinette, future wife of Louis XVI). At this time it was valued at $750,000. The Florentine was mounted in a crown for the coronation of the Duke as Emperor Francis I, Holy Roman Emperor, and remained in the Austrian Crown Jewels until 1918.

At the end of World War I, the Hapsburg Empire came to an end, and the family fled to Switzerland with the stone, now set into a Brooch. No more was seen of the diamond. Whether it was lost or stolen in the post-war confusion is unknown. Rumours have circulated from time to time that it was re-cut or sold privately, but what is sure is that it has not been seen publicly for almost 100 years.


The diamond was also called the following names over its lifetime:

The Tuscan
The Austrian
The Tuscany Diamond
The Grand Duke of Tuscany
The Austrian Diamond
The Austrian Yellow Diamond (not to be confused with the Austrian Yellow Brilliant, another important stone)